<!DOCTYPE html>
<html>
<head>
<style>
a:hover
{
background-color:yellow;
}
p:hover{
    display: block;
}
img{
display: none;
}
#asd:hover img{ 
    display: block;
}
</style>
</head>
<body>

<div id="asd">
<a href="http://www.google.com">Google</a>
<p>显示图片</p>
<img src="scenery1.jpg">
</div>
<p><b>注释：</b>:hover 选择器鼠标指针在其上浮动的链接设置样式。</p>

</body>
</html>